This invention relates to cylindrical electric cells and is particularly, but not exclusively, applicable to alkaline storage cells.
Such storage cells are known in which the electrodes of the thin sintered carrier type are wound in a spiral with one or two interleaved separators. This technology, while enabling the production of storage cells capable of supplying high currents is nevertheless fairly expensive and becomes relatively more expensive as the dimensions of the storage cell are decreased.
There have been proposals to use relatively thicker electrodes in the form of coaxial cylinders which are alternatively positive and negative, the number of coaxial layers of one polarity being then limited to one or two and each cylindrical layer being made of a plurality of cylindrical arcs, for example, two half-cylinders in order to facilitate assembly. A central current collector formed by a metal plate folded in a V, acts as a terminal of one polarity while at the same time urging the half-cylinders radially outwards against one another and against a metal casing which acts as an outer terminal of the other polarity. A disadvantage of such a cell is that the end innermost and outermost electrodes (in the center and at the periphery) have a low efficiency since they are relatively thick and operate with one face only, i.e. the respective faces adjoining the electrodes of opposite polarity.
An object of the present invention is to mitigate this disadvantage at reasonable cost.